This invention relates to a keyboard musical instrument and, more particularly, to an acoustic piano or piano-based musical instrument having a keyboard to be covered with a fall board.
A grand piano and upright piano are major models of an acoustic piano. The grand piano and upright piano each have classical contours, and the user does not want to drastically change the classical contours. FIG. 1 shows a typical example of the grand piano. The piano case 1 gives the unique contour to the grand piano. Three legs 2 downward project from the piano case 1, and keep the piano case 1 over the floor. A lyre box 3 is hung from the piano case 1 by means of lyre posts 4, and pedals 5 frontward projects from the lyre box 3.
A side board 6, an upper beam 7, a key bed 8, a desk board 9, a top board 10 and a fall board 11 are assembled into the piano case 1, and define an inner space. A keyboard 12 is placed on the key bed 8 (see FIG. 2). Though not shown in the drawings, an action mechanism, hammers and dampers are accommodated in the inner space together with strings, and the keyboard 12 is functionally connected to the action mechanism. While a pianist is playing a piece of music on the keyboard 12, the keyboard 12 causes the action mechanism selectively to give rise to free rotation of the hammers. The strings are stretched over the hammers, and are selectively struck with the hammers for generating piano tones.
The top board 10 is hinged at the left side portion thereof to the side board 6, and the inner space is open and closed depending upon the angular position of the top board 10.
The side board 6 has a contour like a wing, and arm portions 6a project onto both side portions of the key bed 8. The upper beam 7 laterally extends over the key bed 8, and is secured at both sides thereof to the side board 6. A slot is defined between the key bed 8 and the upper beam 7. A key slip 13 laterally extends along the front end of the key bed 8, and is secured to the key bed 8 as shown in FIG. 2. The keyboard 12 is placed on the key bed 8. The keyboard 12 is inserted into the inner space through the slot under the upper beam 7, and is functionally connected to the action mechanism (not shown). The front end of the keyboard 12 is at the back of the key slip 13, and is exposable to a pianist who sits on a stool in front of the key slip 13.
The fall board 11 laterally extends over the front portion of the key bed 8, and is rotatably connected at both ends thereof to the arm portions 6a of the side board 6. The fall board 11 is changed between a closed position and an open position. While the pianist is playing the piece of music on the keyboard 12, the fall board 11 is rest against the upper beam 7, and is maintained at the open position. The keyboard 12 is exposed to the pianist at the open position. When the pianist completes the practice, he or she pulls the fall board 11, and gives rise to the rotation. The fall board 11 falls onto the key slip 13 and/or key blocks. Thus, the keyboard 12 is covered with the fall board 12 at the closed position.
The keyboard 12 is fabricated from a key frame 12a, a front rail 12b, a rear frame and a back rail (not shown), balance rail (not shown), balance pins (not shown) and black and white keys 12c. The front rail 12b, balance rail and back rail are spaced from one another in the fore-and-aft direction at intervals, and are secured to the key frame 12a. The balance pins upwardly project from the balance rail at intervals, and the black and white keys 12c are put on the balance rail in such a manner as to be respectively engaged with the balance pins. The balance pins offer axes of rotation to the black and white keys 12c. When a pianist depresses the black/white keys 12c, the front portions are sunk toward the front rail 12b, and the action mechanism is actuated for driving the hammers for the free rotation.
The fall board 11 has a relatively thick boss portion 11a, relatively thin cover portion 11b and a beak portion 11c. Shafts 11d are embedded into the relatively thick boss portion 11a, and sideward project therefrom. The shafts 11d are rotatably supported by suitable brackets embedded in the arm portions 6a. The relatively thin cover portion 11b is merged into the relatively thick boss portion 11a. The relatively thin cover portion 11b is constant in thickness so that the inner surface 11e is flat as shown. The beak portion 11c projects from the relatively thin cover portion 11b, and is gently curved.
When the fall board 11 enters the closed position, the beak portion 11c is held in contact with the key slip 13 and/or rubber buttons on the key blocks, and keeps the cover portion 11b spaced from the black and white keys 12c as indicated by dots-and-dash line in FIG. 2. The heavy fall board 11 as well as the classical contour impresses persons as being a musical instrument of depth.
While the pianist rests the fall board 11 against the upper beam 7, the relatively thin cover portion 11b is upright over the keyboard 12, and the flat inner surface 11e is very close to the land portions 12d of the black keys 12c. When a pianist wants to generate a certain tone assigned a block key 12c, he or she depresses the land portion 12d of the black key 12c. The pianist bends a finger, and presses the tip of the finger against the land portion 12d as indicated by dots-and-dash line. When the pianist changes the finger from the black key 12c to another key 12c, he or she sometimes straightens the finger as indicated by real line, and, thereafter, moves the finger to another key 12c. 
A problem is encountered in that the pianist tends to hit the nail against the inner surface 11e. If the nail is frequently hit against the inner surface 11e, the nail is cracked and broken into two pieces. The fall board 11 is also damaged. When the pianist hits the nails against the inner surface 11e, the inner surface is scratched, and the smoothly finished surface becomes disfigured with the scratches.
It is therefore an important object of the present invention to provide a piano-like musical instrument, a fall board of which allows a player to finger on the keyboard without hitting nails thereagainst.
To accomplish the object, the present invention proposes to form a clearance for allowing a pianist to straighten his or her fingers.
In accordance with one aspect of the present invention, there is provided a keyboard musical instrument comprising a case having a side wall and a bottom plate fixed to the side plate in such a manner as to be located between both side portions of the side wall, a mechanism accommodated in the case, a keyboard placed on the bottom plate so as to be exposed to a space between the side portions and selectively moved for actuating the mechanism, and a fall board rotatably connected to the case so that a user changes the fall board between an open position for standing over the keyboard and a closed position for covering the keyboard therewith and formed with a recess extending along the keyboard so as to offer a clearance to fingers on keys of the keyboard at the open position.